Development of internal combustion engine fuel control apparatus having electronic controlled fuel injectors has heretofore been concerned to a great extent with means and methods involving control of cycle injection timing and the parameters governing the fuel injector open duration. Controlling these variables on liquid fuel consuming engines requires sophisticated control apparatus and electrically controlled fuel injectors for each cylinder of the engine. The high cost and complexity of these components has created a need for a less expensive and simpler alternative. Additionally, the need for controlling vehicular created air pollution has placed increasing emphasis on the use of fuels which burn cleaner and reduce pollution, such as gaseous fuels, including LPG and CNG.
Therefore, the primary object of the present invention is to provide an electronic controlled fuel injection system for gaseous fuels which eliminates cylinder specific controlled fuel injectors and the appurtenant wiring and controls for each cylinder.
A further object of the invention is to provide a system using a single fuel line to a fuel delivery plenum, or fuel rail, in an internal combustion engine which uses gaseous fuel, in which the fuel flow rate in the single fuel line is electronically controlled by a closed loop system capable of adjusting to an optimum fuel flow rate in accordance with the demands of a plurality of engine operating conditions.
A further object of the invention is to provide a system and a controller therefor which can accommodate a single fuel line to a fuel delivery plenum in an internal combustion engine which uses gaseous fuel for either multi-port injection or central point injection, either upstream or downstream of the throttle valve.
Another object of the invention is to provide a means for controlling gaseous fuels to internal combustion engines in a manner which will deliver a fuel quantity which will achieve the optimum fuel/air ratio for the instant operating condition of the engine, while at the same time reducing unwanted exhaust emissions.
Another object of the invention is to provide means for delivering gaseous fuels to an internal combustion engine with the same sophistication and precision as has been done with gasoline delivery systems, but with substantially reduced costs.
Another object of the invention is to provide a fuel flow control unit which can function optimally over a wide range of fuel pressures.
A still further object of the invention is to provide a fuel flow control which will operate linearly over its entire operating range without unwanted spikes or rushes of fuel when the controller first admits fuel to the system, or conversely, prematurely shuts off fuel when demand is reduced.
Also an object of the invention is to provide a fluid flow control device which is regulated by the electrical voltage supplied to the controller and which returns a voltage indicative of the fluid output volume and returns a second voltage indicating the temperature of the fluid leaving the controller so that the two return voltages may be used to compute the mass of the fluid leaving the controller.
Other and further objects, features and advantages of the invention will become apparent upon a reading of the following description of a preferred form of the invention.